Mount assembly for sun lamps



i 3, 1950 M. E. MAcKsoUD MOUNT ASSEMBLY FOR sun LAMPS 3 Sheets-Sheet 1 Filed Feb. 19, 1948 IN V EN TOR.

ct. 3, 1950 M. E. MACKSOUD mourn" ASSEMBLY FOR sun LAMPS 3 Sheets-Sheet 2 Filed Feb. 19. 1948 Inventor Oct. 3, 1950 M. E. MACKSOUD MOUNT ASSEMBLY FOR SUN LAMPS 3 Sheets-Sheet 3 Filed Feb. 19, 1948 Inventor W aw Q1 gaw wmzg Patented Oct. 3, 1950.

. 2,524,455 7 MOUNT ASSEMBLY FOR SUN LAMPS Michel E. Maeksoud, signor to Cooper- Hoboken, N. J.

Newburyport, Mass., as-

ewitt Electric Company Application February 19, 1948, Serial No. 9,558

1 Claim.

This invention relates to improvements in an assembly of component elements of electric lamps which includes a mercury arc discharge tube, and particularly, to an improved mount assembly, for supporting the various lamp components included in the construction of the present day sun lamp.

It is, accordingly, an object of the present invention to provide a compact, efiicient sun lamp assembly within a bulb having a reflecting surface, so as to obtain, in cooperation with the reflecting surface, a sun lamp having a uniformly blended pattern of radiation within the defined area produced by the reflector.

In sun lamps of this type, the usual practise is to provide a mount assembly which includes a mercury. arc discharge tube supported by spaced metallic discs, together with a ballast filament which is mounted at the extreme end of this assembly. These two principal elements of a modern sun lamp, mainly the mercury arc discharge tube and the series connected ballast filament, are usually mounted within the bulb adjacent the focal point of the reflecting surface of the bulb.

A particular feature of this invention resides in a refinement of the positioning of the two principal functioning elements of a modern sun lamp, namely the mercury arc discharge tube and the series connected ballast filament, so that these center of the focusable area of the reflecting surface of the bulb, in order to direct uniform and blended ultra-violet and infra-red radiations of the lamp uponan exposed object.

Another feature of this invention is the separation of the ballast filament into two or more sections, mounted closely adjacent and parallel to the longitudinal axis of the mercury arc discharge tube, which brings more closely together these two sources of radiation within the focusable area of the sun lamp bulb reflector, and

thus considerably improves the eiliciency of the lamp as well as reduces the stabilization time required for optimum radiation transmission characteristics.

Another object of this invention is to utilize the heat produced by the ballast filament when incandescent, in order to reduce the time factor necessary for the arc tube to reach maximum operating characteristics, and maximum emciency. V

A still further object of this invention is to provide a rigid support for the mercury are discharge tube and the series connected ballast filaelements are as close as possible to the' 2 ment which considerably simplifies and strengthens the sun lamp mount assembly.

Reference is made to U. S. Patent No. 2,171,580 and U. S. Patent No. 2,277,876, both issued to Michel E. Macksoud, which include structural means for disposing the ballast filament as close as possible to the mercury arc discharge tube, both elements being mounted within the focus able area of the reflector of the sun lamp bulb. However, a particular object of this present invention is a still further refinement of the structural details of the assembly for the ballast filament. constituting an improvement which makes the entire mount assembly more feasible from a commercial production point of view.

Since this new and novel mount assembly construction establishes and positions the combined two sources of radiant energy; namely, the ultraviolet radiations generated by the mercury :arc discharge tube and the infra-red radiations generated by the incandescent ballast filament, as

closely as possible and both within a defined location withrespect to'the focusable area of the reflector of the sun lamp bulb, a pattern of combined, uniformly blended radiations including both ultra-violet and infra-red radiations are thereby produced by the lamp in a well defined and uniform beam.

These and other features of the'invention will be best understood and appreciated from the description of the structural details of the mount assembly forming a complete unit of a modern type sun lamp. For purposes of illustrations, the accompanying drawings show this complete and novel mount assembly in which,

Fig. 1 is a view in perspective of a complete sun lamp, portions of the bulb being shown as broken away in order to more clearly illustrate the mount assembly structural details.

Fig. 2 is a view in elevation of the complete sun lamp of Fig. 1, but shown in a position with the two separate sections of the ballast filament directly opposite one another.

Fig. 3 is a view in elevation of the complete sun lamp assembly of Fig. 1 with portions of the bulb being shown as broken away so as to illustrate the two separate sections of the ballast filament, positioned and placed on each side of the mercury arc discharge tube.

Fig. 4 is a circuit diagram of the sun lamp components of Fig. 1, showing the improved mount assembly with respect to the location of the various elements included therein, and describes the function of these elements in operation.

The sun lamp of Fig. 1 is shown as comprising beads 4|, having supports 7 alternating current is a bulb I of more or less conventional shape and having ultraviolet transmission characteristics, provided with a metallic coating forming a reflector 3 preferably of aluminum, having a cutof! portion ending in a line 1, substantially the line of maximum diameter of the bulb I. This bulb is provided with a metal lamp screw base 3, which is cemented to the said bulb and has mounted therein, upon th glass stem l l, the improved mount assembly comprising lead wires i3 and I5, metallic platforms l1 and 2|, insulated by insulators 23, and afiixed in position by eyelets all cooperating to support and position within a predetermined focusable area with respect to the reflecting surface 5 of the bulb I; having spaced electrodes 28 and an arc tube 21 a starting coil 30 interconnected in series with the ballast filament divided-into equal sections 43 and 44. This ballast I separate coils 43 and 44 connected in series and supported by the metallic platform 2 I, the hooks '45, the lead electrodes 48. The coils are positioned parallel to and adjacent the longitudinal axis of the mercury arc discharge tube 21. These two separate sections of the ballast coil filament are each firmly supported in theirapproximate centers by the glass insulated 48 and pigtails 41. Also illustrated in this assembly is a thermostatic switch unit, mounted as an integral part of the supporting platform 11, which supports the mercury arc tube 21 and the ballast filament hook connectors .48. (l. v

Fig, 2 is a view inelev'ation of the lamp of Fig. 1 with portions of the bulb being cut away to more clearly illustrate the improved mount assembly construction previously described in the sun lamp of Fig. 1.

Fig; 3 is another view in illustration of a complete sun lamp, but from a. difierent point of view, showing portions of the bulb being shown as broken away to more clearly illustrate the improved mount assembly of the sun lamp of Fig. 1.

Fig. 4 is a circuit diagram which serves to illustrate the relative positioning of the components of the improved mount assembly, in order to more clearly explain the advantages derived from this improved mount assembly when in operation.

Referring to Fig. 4, when an applied voltage of connected to the terminals of the sun lamp base 5| and 53, on one half of the cycle, the current follows the support l3 through one portion of the ballast filament 43, the support hook 45 across the support platform 2|, hook support 45 and through the other section of the ballast filament 44, support connector hook 48, flexible lead connection 38, starting coll filament .30, flexible lead connection 39 through junction 42 affixed to the metalllc'platform H, to terminal point 31 of the bimetallic thermostatic switch element 29 which has a support arm 3| and a stop arm 40 with contacting members 3'5 and 33 at contacting point 35. The electrical circuit is complete through the bi-metallic surfaces 3|, 29, contact arm 36 at contact point through contacting arm 33, which 5 affixed to the lead wire 15 and which continues the circult to the terminal of the base of the lamp 5:. When the current is first applied to tile lamp, the starting coil which is in thecircuit in series with the two sections of the ballast filament and interconnected thereto by the bi-metallic switch, causes heat to be generated within the arc tube as well as ionization of the inert gas content of the tube. Simultaneously, the two sections of filament consists of two the ballast filament becoming incandescent cause a rapid heating of the mercury vapor tube as well as heating of the thermostatic switch ,unit, so that it opens and causes the circuit established in the starting coil to be broken. The heating of the mercury vapor, together with ionization of the inert gas in the arc tube 21, facilitates the striking of anarc between the open oppositely disposed electrodes 28, so that an arc discharge is maintained and completes. the electrical cir' cult which is in series with the ballast filament sections 43 and 44.

It has been found by actual test and comparison that the time consumed in achieving the maximum efliciency of a sun lamp is considerably reduced by the use 'of' this new and improved mount assembly. The improvement in this time factor of stabilizing the operational characteristics, considerably improves the efficiency of this type of sun lamp. I

The two sections of ballast filament illustrated show a conventional form of coiled tungsten filament being supported in closely spaced relation to the longitudinal axis of the mercury vapor arc tube. However, this filament also may be made of a coiled-coil type of tungsten filament, which ma-' terially reduces the length of the filament required. Several adaptations using coiled-coil filaments have been made, and in one particular form asingle coiled-coil filament, rather than two separate sections, was used with considerable success. In the case of coiled-coil tungsten filaments, it has been observed that the non-sag qualities of these filaments are desirable. The ballast filament, divided into two or more equal portions, may be connected either in series or in parallel, in order to meet particular circuit requirements. For simplification of assembly and construction, however, it has been found that a single coiled-coil filament operates satisfactorily and with a considerably improved and uniform pattern of heat radiation.

The ultra-violet radiations produced by the mercury arc discharge tube and the infra-red radiations produced by the incandescent ballast filament are thus brought together to a common focusable point with respect to the reflector of the sun lamp bulb. Theblending of both of these sources of radiations produces a well defined and uniform beam of improved eiilciency, and the degree of infra-red heat radiations with in the predetermined focusable area is considerably increased. This is very desirable inasmuch as exposed areas of the body'may benefit from It is important to note that, in the design of this new mount assembly, the ballast filament may require spacing at the extreme limits of the mount assembly, particularly when glass closely similar to quartz is used for the arc tube. The reason for this is that excessive heat as well as possible electrostatic efi'ects tend to cause a devitrification of this glass on at least one portion of its external surface. This devitrification can be reduced to some degree by first thoroughly glazing, or polishing by heating means, or by firing the external surfaces of this glass tube. It

has been observed that devitrification is often tube. This action may be retarded somewhat by the use of inert gas filling for the lamp, such as argon-nitrogen mixtures, which have a tendency to reduce the cyclic action of the incandescent tungsten ballast fllament. However, the ultimatetype of glass that may be used for mercury arc discharge tubes, for generating a high intensity arc having maximum ultra-violet radiation spectra characteristics is pure quartz. This type of glass has negligible characteristics of devitriflcation.

Having thoroughly disclosed my invention and described the embodiments thereof, but without intending to limit it tion shown, I claim ters Patent: 7

An electric lamp comprising a base, a bulb having a curved reflecting surface extending outwardly from said base, an elongated cylindrical ultraviolet emitting arc discharge tube disposed along the optical axis of the bulb and extending outwardly from said base in axial alignment therewith, upper and lower metallic platforms forming a portion of the circuit surrounding the end portions of said discharge tube and rigidly supporting the same, a refractory incandescent ballwt filament having a plurality of sections,

to the details of construcand desire to secure by Leteach filament section being secured at its ends to said platforms and arranged in close parallel relation to said are tube, each of said filament sections being of sufllcient length to span substantially the full length of said arc discharge tube, and a diffusing frosting on the bulb positioned on the end thereof.

" MICHEL E. MACKSOUD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,017,719 Inman Oct. 15, 1935 2,116,681 Inman May 10, 1938 2,171,580 Macksoud Sept. 5 1939 2,203,550 Spanner June 4, 1940 2,263,171 Hays Nov. 18, 1941 2,265,896 Reger Dec. 9, 1941 2,277,876 Macksoud Mar. 31, 1942 2,404,002 Smith July 16, 1946 FOREIGN PATENTS Number Country Date 222,067 Switzerland Sept. 16, 1942 

